1. Field of the Invention
The present invention relates to an exhaust gas purifying filter that collects particulate matter, such as fine carbon particles emitted from internal combustion engines, and oxidizes and removes the particulate matter by a catalytic reaction, and to a method of manufacturing the same.
2. Description of the Related Art
For the purification of particulate matter emitted from an internal combustion engine, a method has been conceived where an exhaust gas purifying filter is used to collect the particulate matter and the particulate matter is burned and removed by a heater that is disposed at a proper position.
The exhaust gas purifying filters used for this method include the one, for example, that is described in Japanese Unexamined Patent Publication (Kokai) No. 9-77573 and has regulated diameters of the pores included in the surface of dividing walls of honeycomb structural body, made of ceramic, that constitutes the exhaust gas purifying filter, in order to improve the efficiency of capturing the particulate matter on the dividing wall surface.
Regarding the operating principle of the exhaust gas purifying filter, it has been recently proposed to coat the dividing wall surface the honeycomb structural body with a catalyst and continuously burn the particulate matter using a catalytic reaction.
However, when a honeycomb structural body similar to that used for burning and removing the particulate matter by means of the heater as in the prior art is used, there is a problem that the particulate matter cannot be sufficiently burned and removed by the catalyst reaction, for practical use, simply by replacing the heater with the catalyst.